Airdog 150 question

[Cummins_04]

I can't seem to get a straight answer. If my truck is running and I open the valve on the water seperator should fuel come out? Mine only does it when it is off. I have been told it should drain while running and also told it would only drain when off. So which is right? I'm trying to find out if the Airdog is causing problems with me truck

 

[w250_93]

The water drain is on the suction side of the pump so no it will not drain while running, it'll just suck air.